Why do you administer a Beta Blocker before CABG? Are there any contraindications?
It's to help prevent postoperative atrial fibrillation, and in fact is included in the STS database that collects information on patients in participating facilities. Contraindications would be the same as the contraindications you'd hold it for in any patient taking a beta blocker- HR and BP parameters per provider order or facility protocol. There are a few others, including COPD and vasoactive drips running.
An article that might help explain: Beta-blockers for patients undergoing CABG : Nursing2 17